Can’t all interpreters translate documents , and all translators interpret orally?
No. Translation and interpretation are different skills, though both language-related. An analogy would be that a criminal attorney does not necessarily know patent law well enough to practice it tomorrow morning. A ballet dancer does not necessarily dance swing. Some, but not all, interpreters are well versed in written translations as well; however, most professional translators have never worked as interpreters. Competency examinations test for different skills in each category. (For example, at the United Nations, the Interpretation Department is a wholly separate entity from the Translation Department.) For court work, the lines are not so clearly drawn, but it depends entirely on the nature of the assignment. For example, tape transcripts are a hybrid form, part oral and part written, and some interpreters specialize in preparing them. But one cannot assume that any interpreter will be able to produce a good transcript. Different areas of the brain are used in these disciplines.
